1. Field of Invention
The invention relates to an electrophotographic image forming apparatus, such as a laser printer.
2. Description of Related Art
Electrophotographic image forming apparatus are well known in the art. These devices, such as a laser printer, typically include a photosensitive drum, a charger, a laser scanner, a developing roller, and a transfer roller. After the surface of the photosensitive drum is uniformly charged by the charger, the surface of the photosensitive drum is irradiated with a laser beam emitted from the laser scanner, and an electrostatic latent image is formed based on predetermined image data.
Toner carried on the developing roller is supplied to the electrostatic latent image formed on the surface of the photosensitive drum. The toner deposited on the surface of the photosensitive drum is transferred to a sheet passing between the photosensitive drum and the transfer roller.
The developing roller is rotatably attached to a developing cartridge. The developing cartridge is provided with sealing elements to prevent toner from leaking from both ends of the developing roller with respect to an axial direction thereof. The sealing elements are placed so as to make sliding contact with the circumferential surface of the developing roller, at both ends of the inside of the developing cartridge with respect to the axial direction of the developing roller when mounted in the developing cartridge in position.